The Historia fundationis cum fundatoris genealogia of Abergavenny Priory named Margaretam, Bertram and Luciam as the three daughters of Miles and Sibyl.
[citation needed] She married Humphrey II de Bohun, an Anglo-Norman aristocrat and steward of King Henry I of England, on an unknown date before 1139.
Like Margaret's father, Humphrey later supported Empress Matilda against her rival King Stephen during the period of civil war that raged over England, known to history as The Anarchy.
[6] Margaret died on 6 April 1197 and was buried in Llanthony Secunda Priory in Gloucester which had been founded by her father and where her mother, Sibyl had entered a religious life after her husband's untimely death.
Two years following Margaret's death, King John confirmed the possessions of Llanthony Secunda Priory by charter which was dated 30 July 1199.
[citation needed] On 28 April 1200, King John recreated the earldom of Hereford for Margaret's grandson Henry, of whom she had had custody during his minority.